45,031 research outputs found
An obstruction for q-deformation of the convolution product
We consider two independent q-Gaussian random variables X and Y and a
function f chosen in such a way that f(X) and X have the same distribution. For
0 < q < 1 we find that at least the fourth moments of X + Y and f(X) + Y are
different. We conclude that no q-deformed convolution product can exist for
functions of independent q-Gaussian random variables.Comment: The proof of proposition 2 is corrected on 11 january 199
Book Review on The Philosophical Challenge from China (Edited by Brian Bruya)
In this paper, I review the book The Philosophical Challenge from China, edited by Brian Bruya. I critically discuss each of the 13 contributions
Open-ocean interior moored sensor turbulence estimates, below a Meddy
A one-year time series of moored high-resolution temperature T-sensor data
from 1455 m depth on a 3900 m long line in about 5300 m of water in the
NE-Atlantic Canary Basin are dominated by salinity (over-)compensated
intrusions arising from the effects of Mediterranean outflow waters, which are
commonly organized as Meddies. During the passage of a Meddy-core above the
T-sensors, no intrusions were observed, thereby making it possible to use the
temperature records to quantify turbulence parameters. The present data show
that these ocean-interior turbulence estimates are from short-lived (less than
0.5 h) rather intense overturning cells with vertical scales of <5 m. Because
the turbulence inertial subrange is found to extend into the internal wave
band, the overturns are predominantly driven by shear associated with inertial
currents. Kinetic energy, current shear and temperature variance peak at
sub-inertial frequencies during the Meddy passage, suggesting wave trapping in
the warm anti-cyclonic eddy and/or weakly stratified layers. The observations
further show that internal wave displacements are coherent over vertical scales
of up to 40 m during the presence of the Meddy compared with vertical coherence
scales of less than 25 m during the more common no-Meddy conditions of double
diffusion intrusions.Comment: 32 pages, 9 figure
Most Peers Don’t Believe It, Hence It Is Probably False
Rob Lovering has recently argued that since theists have been unable, by means of philosophical arguments, to convince 85 percent of professional philosophers that God exists, at least one of their defining beliefs must be either false or meaningless. This paper is a critical examination of his argument. First we present Lovering’s argument and point out its salient features. Next we explain why the argument’s conclusion is entirely acceptable for theists, even if, as we show, there are multiple problems with the premises
Migration and child labour: Exploring child migrant vulnerabilities and those of children left-behind
This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.ILO_MigrationandChildLabour.pdf: 1627 downloads, before Oct. 1, 2020
Multilevel Sparse Grid Methods for Elliptic Partial Differential Equations with Random Coefficients
Stochastic sampling methods are arguably the most direct and least intrusive
means of incorporating parametric uncertainty into numerical simulations of
partial differential equations with random inputs. However, to achieve an
overall error that is within a desired tolerance, a large number of sample
simulations may be required (to control the sampling error), each of which may
need to be run at high levels of spatial fidelity (to control the spatial
error). Multilevel sampling methods aim to achieve the same accuracy as
traditional sampling methods, but at a reduced computational cost, through the
use of a hierarchy of spatial discretization models. Multilevel algorithms
coordinate the number of samples needed at each discretization level by
minimizing the computational cost, subject to a given error tolerance. They can
be applied to a variety of sampling schemes, exploit nesting when available,
can be implemented in parallel and can be used to inform adaptive spatial
refinement strategies. We extend the multilevel sampling algorithm to sparse
grid stochastic collocation methods, discuss its numerical implementation and
demonstrate its efficiency both theoretically and by means of numerical
examples
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